Abstract: Disclosed are methods of enriching collagen fragments in a sample comprising combining a sample comprising collagen fragments with a composition comprising any one of the dimeric CHPs described herein, and wherein the first CHP and second CHP bind to and form a triple helix with a collagen fragment; and removing the bound collagen fragments from the dimeric CHP providing a product enriched with collagen fragments. Disclosed are methods of detecting collagen in a sample comprising enriching collagen fragments from a sample, wherein enriching the collagen fragments comprises combining a sample comprising collagen fragments with a composition comprising a dimeric CHP, wherein the dimeric CHP comprises a first CHP and a second CHP, one or more linkers, and a branch point, wherein the collagen fragments bind the dimeric CHP; and detecting the binding of the collagen fragments to the dimeric CHP.